Switch-board for telephones



(No Model.)

H. CLAY. SWITCH BOARD POR TELEPHONES.

Patented July 3, 1883.

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WITNESSES:

NA PETERS. PhelwLilhogmpher. Washington D.C.

UNITED; STATES PATENT QPEICE.V

HENRY cLAY, E PHILADELPHIA, PENNSYLVANIA.

SWITGH-BOARD FOR TELEPHONE-IS.

SPECIFICATION forming part of Letters Patent No. 280,351, dated July 3, 1883.

Application filed September 2l, 1882. (No model.)

To all whom t may concern:

Beit known that 1 HENRY CLAY, a citizen of the United States,l residing inthe city and county of Philadelphia, State of Pennsylvania, have invented a new and useful Improvement in Switch-Boards for Telephones, which improvement is fully set forth in the following specification and accompanying drawings, in which- Figure 1 is a side elevation and partial se'ction of the switch-board embodying my invention. Figs. 2 and 3 are top views of the parts thereof. Fig. 4 is an end view of Fig. 3.

Similar letters of reference indicate corresponding parts in the several figures.,

My invention consists of certain improvements in switch -boards for telephone-exchanges, the construction, operation, and advantages being hereinafter fully set forth.

Referring to the drawings, A represents a perforated metallic plate in electrical connection with the telephone at the central oiiice,

. and B represents a magnet Awhich is properly supported on a base, A is attached.

C represents an armature for the electromagnet B. This armature is mounted on the base B, and two catches, D D, are pivoted to it at the end opposite to said magnet. Two

B', with which the plate levers, E E, are pivoted to the said base, and

are arranged to abut, respectively, against the said catches D D when in `normal position. This position is upright, as shown in the drawings 5 but a horizontal or inclined arrangement may be adopted instead. Said levers are provided with springs or weights for holding each of them in said normal position, and they are insulated from said catches. at the points of contact. They are also insulated from each other by the base B', which is anon-conductor of electricity.

F represents the line-wires which lead to the different subscribing-stations, each wire depending from the plate A through one of the perforations thereof, andhaving at top a metallic piece, G, which is held in contact with the wall of the perforations of the plate A, the wire having an attached weight, H, or being otherwise weighted to insure the contact of the 5o piece G and plate A. The top of each wire terminates in an eye, J, which, when the wire is raised, may be iitted on either of the two levers E, and to each wire, between said eye and the piece G, is secured an insulating-plug, K, whereby the wires may be handled and operated with safety.

To complete the circuit, a wire extends, as shown, from ground 1 to the telephonic apparatus or instrumentof the subscriber ony line 31. The circuit is then through said ground 6o mechanism of said signa-li11g-instrument to close the circuit with the central office through the connections above described. After the central office learns the requisition from subscriber No. 31, the operator takes the eye Ji of linewire F31, and attaches it to lever E. lIn sodoing, the eye I is necessarily brought into elec` trical contact w`1th the catch D for said lever, and lifts said catch. As this catch is in mev tallic connection with the generator bymeans of wire C, a momentary circuit is established through the telephone of subscriber 31, and this produces a gurgling noise, which notiiies him that his requisition is attended to. The wire F and eye J of the subscriber who is called forare then manipulated in like manner, and when said metallic eye raises the catch D, with which it comes in contact, it completes a momentary circuit for said subscribers notiiication through said catch and 9o strument 37 of this latter subscriber of course loo has ground-connections and linefwire connections similar to those of instrument 31. The m Both the eye .FL of the first-named circuit is then from ground of instrument 3l through its groundwire, said instrument, line- Wire F, eye J 31, lever E, through Wire to magnet B, from magnet B through Wire to the other lever on which eye J 37 is hung, thence through said .eye and the line-Wire F37, through the instrument of Subscriber 37 and its ground-Wire to ground. When the parties 31 and 37 have finished talking, the telephones of their instruments are hung upon the respective hooks of their call-bells or signaling apparatus, which causes the mechanism of the latter to be set in motion.

tion for said call-bell mechanism, and this current (which follows the circuit last described) is of sufficient strength to magnetize the cores of magnet B and attract armature C, thereby raising the catches D from the levers E. The Weights H ofthe respective telephone Wires F will then cause the said levers to turn outvWardly until the eyes J drop off from them,

This generates a current of electricity, as described in my separate applica- 1. The perforated metallic plate in electrical connection With the central-ofiice telephone, in combination with catches D and gravitating Wires, which are held in contact With said plate when not in use, and adapted to be moved to form a circuit through said catches and the central-office generator While placing different subscribers in communication.

2. The perforated metallic plate connected With the central-office telephone, in combination with, the Wires havingl metallic pieces G, substantially as and for the ,purpose set forth.

3. The combination of the line-Wires having the eyes J, with the levers E and perforated plate, substantially as set forth.

4. The magnet B, in combination with the armature C, having. catches D, and the levers E, the magnet being included in a circuit between said levers, substantially as and for the purpose set forth.

5. The perforated plate, in combination with the Wires having metallic pieces G, eyes J, and insulating-plugs K, substantially as and for the purpose set forth.

HENRY CLAY.

Vitnesses:

J oHN A. WIEDERsHEiM, W. F. KIRCHER. 

